Residue Free TaN Etch Method for MIM Capacitor in Advanced Packaging

This study presents a novel approach to fabricate Tantalum Nitride (TaN) based Metal-Insulator-Metal (MIM) capacitors, which are essential for enhancing power integrity in advanced packaging applications. TaN is a critical electrode material of MIM capacitors due to its high thermal stability and excellent diffusion barrier property. However, the Ta based residue is a critical challenge for TaN MIM capacitors fabrication. An innovative, residue free TaN etch method is developed by synergistically optimizing plasma etch and wet clean. The plasma etch with highly volatile by-products significantly reduces Ta residues. Combining a lift-off wet clean, this etch method can realize residue free TaN MIM capacitors fabrication. The synergistic process development scheme in this study will be inspiring for the fabrication process development of advanced packaging with increasing complexity.